A new generation of network streamers from Naim

Digital inputs extend to coaxial on RCA and BNC, optical and USB for disc drives, there are dual wi-fi antennas for situations where Ethernet connection is not available. The two bigger models have a five inch colour TFT screen that is engineered so that data transfer is switched off when the image is static in order to keep down noise. In fact noise reduction is the essence of this range, because it’s the enemy of sound quality in digital systems. Each ND has a switch mode supply so that it can remain ready for action without exceeding energy efficiency regs on standby (0.5W) but this hands over to a linear supply when the streamer is operating. They also share a SHARC DSP that provides 16x integer oversampling with Burr Brown DAC chips operating purely as converters with none of their filtering or other features engaged.

The ND5XS 2 omits the display or any control buttons. Naim’s thinking being that users will operate all of these streamers with the app (iOS, Android). There is also no power supply upgrade options on the entry level player. It has a BurrBrown 1791A DAC, RCA or DIN analogue output and switchable earthing. The NDX 2 adds the option of adding an external power supply such as an XPS PSU or PS555, but also has a substantial transformer on board, big enough to be in one of Naim’s power amps in fact. This model has the TFT display with which you have the option of white or green text alongside the album artwork shown when streaming. You get an RF remote handset with this model and discrete filter circuits rather than the op-amps of the current NDX.

All the best stuff is held back for the flagship ND 555 where no screw torque has been left unchecked in the quest for maximum sound quality. Those screws hold the lid on the case for the streaming engine to protect it from noise, but this is just one example of the extremes that engineers Roy George and Steve Sells have gone to. Others include the direction of internal wiring the use of custom made polystyrene capacitors on the output stage, WBT Nextgen RCA sockets and a suspension system that uses brass weights to keep out vibration above 10Hz. The internal power supply uses DR regulators for the first time in a streamer, an approach that drops the noise floor by a claimed 15dB over the previous LM13 regulators. The way that clocking is done has also changed, the DAC clock runs the Ethernet input rather than the two being slaved together, an approach that Naim thinks is unique to this machine. The ND 555 requires the seperate 555 P/S to operate and can be upgraded further with the addition of a second one.